Engine lather, working, types, holding devices,automatic lathes

1. D.KRISHNAIAH
ASSOC.PROF

2. LATHE
• Lathe is machine, which removes metal from a
piece of work to the required shape and size.
• Lathe is one of the most important machine
tool in the metal working industry.
• A lathe operate on the principle of a rotating
work piece and a fixed cutting tool.
• The cutting tool is feed into the workpiece,
which rotates about its own axis, causing the
workpiece to be formed to the desired shape.

3. Treadle Wheel Lathe

8. • Computer controlled lathe:

9. Modern Engine Lathe
• Electric Motor
• Tolerances of 0.001 inch
• Multiple Screws
• Geared Head
– Variable Spindle Speeds (Rotation)
– Variable & Accurate Feeds (Tool Movement)

11. • Lathe is the oldest machine tool invented,
starting with the Egyptian tree lathes.
• It is the father of all machine tools
• Its main function is to remove material from a
work piece to produce the required shape and
size
• This is accomplished by holding the work
piece securely and rigidly on the machine and
then turning it against the cutting tool
• Cutting tool will remove material from the
work piece in the form of chips.

12. • Working Principle: The lathe is a machine
tool which holds the workpiece between two
rigid and strong supports called centers or in a
chuck or face plate which revolves. The cutting
tool is rigidly held and supported in a tool post
which is fed against the revolving work. The
normal cutting operations are performed with
the cutting tool fed either parallel or at right
angles to the axis of the work.

13. Parts of the Lathe

15. LATHE PARTS

18. Lathe Accessories
• Divided into two categories
– Work-holding, -supporting, and –driving devices
• Lathe centers, chucks, faceplates
• Mandrels, steady and follower rests
• Lathe dogs, is a device that clamps around the work
piece and allows the rotary rotation
– Cutting-tool-holding devices
• Straight and offset tool holders
• Threading tool holders, boring bars
• Turret-type tool posts

19. Lathe Bed
• Heavy, rugged casting
• Made to support working parts of lathe
• On top section are machined ways
– Guide and align major parts of lathe

20. Setting Speeds on a Lathe
• Speeds measured in revolutions per minute
– Changed by stepped pulleys or gear levers
• Belt-driven lathe
– Various speeds obtained by changing flat belt and
back gear drive
• Geared-head lathe
– Speeds changed by moving speed levers into proper
positions according to r/min chart fastened to
headstock
Safety Note!! NEVER change speeds
when lathe is running.

21. Lathe Centers
• Work to be turned between centers must have
center hole drilled in each end
– Provides bearing surface
• Support during cutting
• Most common have
solid Morse taper shank
60º centers, steel with carbide tips
• Care to adjust and lubricate occasionally

22. Chucks
• Used extensively for holding work for
machining operations
– Work large or unusual shape
• Most commonly used lathe chucks
– Three-jaw universal
– Four-jaw independent
– Collet chuck

23. Types of Lathe Dogs
• Standard bent-tail lathe dog
– Most commonly used for round
workpieces
– Available with square-head setscrews of headless
setscrews
• Straight-tail lathe dog
– Driven by stud in driveplate
– Used in precision turning

25. Types of Lathe Dogs
• Safety clamp lathe dog
– Used to hold variety of work
– Wide range of adjustment
• Clamp lathe dog
– Wider range
than others
– Used on all shapes

26. Left-Hand Offset Toolholder
• Offset to the right
• Designed for machining work close to chuck or
faceplate and cutting right to left
• Designated by letter L

27. Right-Hand Offset Toolholder
• Offset to the left
• Designed for machining work close to the
tailstock and cutting left to right
– Also for facing operations
• Designated by letter R

28. Straight Toolholder
• General-purpose type
• Used for taking cuts in either direction and for
general machining operations
• Designated by letter S

29. Lathe parts
• 1.Bed: The bed is a heavy, rugged casting in
which are mounted the working parts of the
lathe.
• 2. Legs: The legs carry the entire load of machine
and are firmly secured to floor by foundation
bolts.
• 3. Headstock: It serves as housing for the driving
pulleys, back gears, headstock spindle, live centre
and the feed reverse gear.
• 4. Gear Box: The quick-change gear-box is placed
below the headstock and contains a number of
different sized gears.

30. Lathe Parts
• 5. Carriage: The carriage is located between the headstock and
tailstock and serves the purpose of supporting, guiding and
feeding the tool against the job during operation. The main parts
of carriage are:
• a). The apron is fastened to the saddle and it houses the gears,
clutches and levers required to move the carriage or cross slide.
The engagement of split nut lever and the automatic feed lever
at the same time is prevented she carriage along the lathe bed.
• b). The saddle is an H-shaped casting mounted on the top of
lathe ways. It provides support to cross-slide, compound rest and
tool post.
• c). The cross slide is mounted on the top of saddle, and it
provides a mounted or automatic cross movement for the cutting
tool.
• d). The compound rest is fitted on the top of cross slide and is
used to support the tool post and the cutting tool.
• e). The tool post :tool holder at the proper height relative to the
work centre line.

31. Lathe parts
• Tailstock: The tailstock can slide along the bed
to accommodate different lengths of
workpiece between the centers.
• A tailstock clamp is provided to lock the
tailstock at any desired position.
• The tailstock spindle has an internal taper to
hold the dead Centre
• And the tapered shank tools such as reamers
and drills.

32. LATHE OPERATIONS
• 1 Plain Turning: Plain turning is the operation of
removing excess amount of material from the
surface of a cylindrical job.
• 2. Step Turning: Step turning produces various
steps of different diameters.
• 3. Facing:by which the end surface of the work
piece is made flat by removing metal from it.
• 4. Parting: dividing the workpiece in two or more
parts
• 5. Drilling: producing a cylindrical hole in the
workpiece

33. • 6. Reaming:It finishes and sizes the hole
already drilled into the workpiece.
• 7. Boring:The boring operation is the process
of enlarging a hole already produced by
drilling.
• 8. Knurling:The knurling is a process of
embossing (impressing) a diamond-shaped or
straight-line pattern into the surface of
workpiece.

34. • 9. Grooving:the act of making grooves of
reduced diameter in the workpiece.
• 10. Threading: the act of cutting of
the required form of threads on the
internal or external cylindrical surfaces.
• 11. Forming:is an operation that produces a
convex, concave or any irregular
profile on the workpiece.
• 12. Chamfering:removes the burrs and sharp
edges, and thus makes the handling safe.

35. • 13. Filing and Polishing:That removes burrs,
sharp corners and feed marks from the
workpiece. with the help of emery cloth of
fine grades
• 14. Taper Turning: Producing a conical surface
by gradual reduction in the diameter of a
cylindrical workpiece.

36. LATHE OPERATIONS

37. TYPES OF LATHE
• 1. Bench Lathe:
• 2. Speed Lathes:
• 3. Engine Lathe:
• 4. Tool Room Lathe:
• 5. Capstan and Turret Lathe:
• 6. Automatic Lathe:
• 7. Special Purpose Lathes:

38. • Bench Lathe:It is a very small lathe and is
mounted on a separately prepared bench or
cabinet.
• It is used for small and precision work since it
is very accurate.
• Speed Lathes: they may have the supporting
legs cast and fitted to the bed.
• They have no gear box, carriage and the lead
screw. With the result, the tool is fed and
actuated by hand.
• Such lathes are usually employed for wood
turning, polishing, centring and metal
spinning, etc

39. • Engine Lathe: It is probably the most widely
used type of lathe.
• . Its headstock is bigger in size, headstock
spindle may receive power, provide different
speeds to the spindle.
• The lathe is known as geared head lathe.
• Tool Room Lathe: same engine lathe but
equipped with some extra attachments to
make it suitable for a relatively more accurate
angle of speeds and feeds.
• It is made to have a comparatively smaller bed
length than the usual engine lathe.

40. • Capstan and Turret Lathe: vastly used in mass
production.
• a very wide range of operations can be
performed on them.
• These machines are actually of semi-automatic
type
• In operating these machines, a very little skill is
required of the operator.
• Setting of tools has been successfully
accomplished further operation of these
machines is more or less automatic.

41. Difference between TL and CL
TURRET LATHE CAPSTAN LATHE
Tool head is directly fitted on saddle.
Saddle is moved to provide feed to the tool
Tool head is mounted on a slide called ram.
To provide feed to the tool, saddle is locked at
a particular point and the ram is moved
It is difficult to move the saddle for feed It is easy to move the ram for feed
As the saddle can be moved along the entire
length of the bed, it is suitable for longer
workpices
As the movement of the ram is limited, it is
suitable for machining shorter workpices
only.
Limit dogs are used to control the distance of
tool movement.
To control the distance of tool movement,
feed stop screws are provided at the rear side
of the turret.
Some turret lathes have the facility of moving
the turret at right angles to the lathe axis
No such facility
Heavy Lighter in construction
Suitable for machining heavy and large
workpices
Only small and light workpices are machined
Machining can be done by providing more Only limited amount of feed and depth of cut

45. • Automatic Lathe: Enhancing the quality as well as
the quantity of production.
• all the working and job handling movements of
the complete manufacturing process for a job are
done automatically.
• No participation of the operator is required
during the operation.
• Automatic lathes are available having single or
multi spindles.
• They fall in the category of heavy duty, high
speed lathes mainly employed in mass
production.

46. • Special Purpose Lathes: Lathes are designed
to suit a definite class of work and to perform
certain specified operations only.
Name of Machine Special Description Application
Precision Lathe Capable of giving a
dimensional accuracy of
0.002 mm
Precision turning of
previously rough-turned
workpiece
Facing Lathe the carriage is driven by a
separate motor,
independent of the main
spindle. It carries no
tailstock
Used to machine the end
faces of bulky cylindrical
jobs.
Vertical Lathe It carries a vertical column,
on which are fitted the cross
slide and vertical slide.
These machines are
specifically employed for
jobs like heavy flywheels
and large gear blanks etc.

47. • Frontal Lathe: machining short jobs
• Crankshaft Lathe: turning very long parts such
as turbine and engine shafts and crankshafts.
• Production Lathe: suitable for mass
production of cylindrical parts.
• Duplicating Lathe: It is used for mass
production of identical parts where either a
previously machined part works as a template
• Screw Cutting Lathe :for mass production of
screwed parts

48. TAPER TURNING
• When the diameter of a piece changes uniformly
from one end to the other, the piece is said to be
tapered.
• It is gradual reduction in diameter from one part of a
cylindrical workpiece to another part
• Tapers can be either external or internal.
• There are three basic methods of turning tapers with
a lathe.
• the operator will either use
• the compound rest, offset the tailstock, or use the
taper
• attachment

49. Compound Rests
• The compound rest is favorable for turning or
boring short, steep tapers,
• it can also be used for longer, gradual tapers
providing the length of taper does not exceed the
distance the compound rest will move upon its
slide.
• This method can be used with a high degree of
accuracy, but is somewhat limited due to lack of
automatic feed and the length of taper being
restricted to the movement of the slide.

50. taper

55. • The compound rest base is graduated in
degrees and can be set at the required angle
for taper turning or boring.
• The angle of the taper with the centerline is
• one-half the included angle and will be the
angle the compound rest is set for.
• For example, to true up a lathe center which
has an included angle of 60°, the compound
rest would be set at 30° from parallel to the
ways

56. • For example, the compound rest setting for
the workpiece shown in Figure would be
calculated in the following manner
• TPI = D - d / L
• angle = TAN (TPI)/2
• Where TPI = taper per inch
• D = large diameter,
• d = small diameter,
• L = length of taper
• angle = compound rest setting

57. • The problem is actually worked out by
substituting
• numerical values for the letter variables:
• TPI = 1.000 - 0.375/0.750
• TPI = 0.625/0.750
• TPI= 0.833
• Apply the formula to find the angle by
substituting the
• numerical values for the letter variables:
• angle = TAN (0.833)/2
• angle = TAN 0.41650

58. CARE AND MAINTENANCE OF LATHES
• Lathes are highly accurate machine tools
designed to operate around the clock if
properly operated and maintained.
• Lathes must be lubricated and checked for
adjustment before operation.
• Improper lubrication or loose nuts and bolts
can cause excessive wear and dangerous
operating conditions.

59. • The lathe ways are precision ground surfaces
and must not be used as tables for other tools
and should be kept clean of grit and dirt.
• The lead screw and gears should be checked
frequently for any metal chips that could be
lodged in the gearing mechanisms.
• Check each lathe prior to operation for any
missing parts or broken shear pins.
• Change the lubricant frequently if working in
dusty conditions.

60. SAFETY
• Must know all safety precautions to avoid
accidents and injuries.
• Carelessness and ignorance are two great
menaces to personal safety.
• Correct dress is important, remove rings and
watches, roll sleeves above elbows.
• Always stop the lathe before making
adjustments.

61. • Do not change spindle speeds until the lathe
comes to a complete stop.
• Handle sharp cutters, centers, and drills with
care.
• Remove chuck keys and wrenches before
operating
• Know where the emergency stop is before
operating the lathe.
• Never attempt to measure work while it is
turning

62. TOOLS AND EQUIPMENT
• GENERAL PURPOSE CUTTING TOOLS: The lathe
cutting tool or tool bit must be made of the correct material
and ground to the correct angles to machine a workpiece
efficiently.
• The most common tool bit is the general all-purpose bit
made of high-speed steel.
• HSS generally inexpensive, can handle the high heat that is
generated during cutting and are not changed after cooling.
• Tool bits made from special materials such as carbides,
ceramics, diamonds, cast alloys are able to machine
workplaces at very high speeds but are brittle and
expensive.

63. • Shapes of Tool Bits: The overall shape of the
lathe tool bits can be rounded, squared, or
another shape as long as the proper angles
are included.
• A right-hand turning tool bit is shaped to be
fed from right to left.
• A left-hand turning tool bit is the opposite of
the right-hand turning tool bit, designed to cut
when fed from left to right.
• This tool bit is used mainly for machining close
in to a right shoulder.

65. • The parting tool bit, is also
known as the cutoff tool bit.
• This tool bit has the principal
cutting edge at the squared end
of the bit that is advanced at a
right angle into the workpiece.
• Besides being used for parting operations, this
tool bit can be used to machine square corners

66. • . Thread-cutting tool bits, are ground to cut
the type and style of threads desired.
• Thread-cutting tool bits can be ground for
standard 60° thread forms or for square,
Acme, or special threads.

67. SPECIAL TYPES OF LATHE CUTTING
TOOLS
• Besides the common shaped tool bits, special
lathe operations and heavy production work
require special types of cutting tools.
• Tungsten carbide, tantalum carbide, titanium
carbide, ceramic, oxide, and diamond-tipped tool
bits and cutting tool inserts are commonly used in
high-speed production work .
• when heavy cuts are necessary and where
exceptionally hard and tough materials are
encountered

68. • Specially formed thread cutter mounted in a
thread “cutter holder
• This tool is designed for production high
speed thread cutting operations
• The special design of the cutter allows for
sharp and strong cutting edges
• The cutter mounts into a special tool holder
that mounts to the lathe tool post

69. • The common knurling tool: consists of two
cylindrical cutters, called knurls, which rotate
in a specially designed tool holder. The knurls
contain teeth which are rolled against the
surface of the workpiece to form depressed
patterns on the workpiece.

94. Classification of automatic lathes

95. Manufactured by CNC M/C

96. Constructional Features And Uses Of General Purpose
Semiautomatic And Automatic Lathes.
• Automation is incorporated in a machine tool
or machining system as a whole for higher
productivity with consistent quality aiming
meeting the large requirements and overall
economy.
• automation enables quick and accurate
auxiliary motions, i.e., handling operations like
tool – work mounting, bar feeding, tool
indexing etc.

97. • These systems may be of mechanical, electro-
mechanical, hydraulic or electronic type or their
combination .
• according to degree of automation machine tools
are classified as,
• Non automatic where most of the handling
operations irrespective of processing operations,
are done manually, like centre lathes etc.
• Semiautomatic
• Automatic where all the handling or auxilliary
operations as well as the processing operations
are carried out automatically.

98. • The conventional general purpose automated
lathes can be classified as,
• (a) Semiautomatic :
– 1. capstan lathe (ram type turret lathe)
– 2. turret lathe
– 3. multiple spindle turret lathe
– 4. copying (hydraulic) lathe
• (b) Automatic :
– • Automatic cutting off lathe
– • Single spindle automatic lathe
– • Swiss type automatic lathe
– • multiple spindle automatic lathes

99. Semiautomatic lathes
• The characteristic features of such lathes are ;
• some major auxiliary motions and handling
operations like bar feeding, speed change, tool
change etc. are done quickly and consistently
with lesser human involvement
• the operators need lesser skill and putting lesser
effort and attention
• suitable for batch or small lot production
• costlier than centre lathes of same capacity

100. Capstan and Turret lathes
• The semi-automatic lathes, capstan lathe and
turret lathe are very similar in construction,
operation and application. Fig. schematically
shows the basic configuration of capstan lathe

101. Schematic configuration of
CAPSTAN LATHE fig.1

102. Schematic configuration of
Turret lathe Fig.2

103. In contrast to centre lathes, capstan and turret lathes
• are semiautomatic
• It possess an axially movable indexable turret (mostly hexagonal)
in place of tailstock
• holds large number of cutting tools; upto four in indexable tool
post on the front slide
• one in the rear slide and upto six in the turret (if hexagonal) as
indicated in the schematic diagrams.
• are more productive for quick engagement and overlapped
functioning of the tools in addition to faster mounting and
feeding of the job and rapid speed change.
• enable repetitive production of same job requiring less
involvement, effort and attention of the operator for pre-setting
of work–speed and feed rate and length of travel of the cutting
tools
• are relatively costlier
• are suitable and economically viable for batch production or
small lot production.

104. There are some differences in between capstan and
turret lathes such as,
• Turret lathes are relatively more robust and heavy
duty machines
• Capstan lathes generally deal with short or long rod
type blanks held in collet, whereas turret lathes
mostly work on chucking type jobs held in the quick
acting chucks
• In capstan lathe, the turret travels with limited stroke
length within a saddle type guide block, called
auxiliary bed, which is clamped on the main bed as
indicated in Fig

105. • whereas in turret lathe, the heavy turret being
mounted on the saddle which directly slides with larger
stroke length on the main bed as indicated in Fig.2
• One additional guide rod or pilot bar is provided on the
headstock of the turret lathes as shown in Fig.2, to
ensure rigid axial travel of the turret head
• External screw threads are cut in capstan lathe, if
required, using a self opening die being mounted in
one face of the turret,
• whereas in turret lathes external threads are generally
cut, if required, by a single point or multipoint chasing
tool being mounted on the front slide and moved by a
short leadscrew and a swing type half nut.

106. • Multiple spindle Vertical Turret lathe
• Turret lathes are mostly horizontal axis single spindle
type.
• The multiple spindle vertical turret lathes are
characterised by :
• Suitably used for large lot or mass production of jobs of
generally ;
– chucking type
– relatively large size
– requiring limited number of machining operations
• Machine axis – vertical for
– lesser floor space occupied
– easy loading and unloading of blanks and finished jobs
– relieving the spindles of bending loads due to job weight.
• Number of spindle – four to eight.

107. • vertical turret lathes are of three categories
• 1.Parallel processing type :
• The spindle carrier remains stationary.
• Only the tool slides move with cutting tools
radially and axially.
• Identical jobs (say six) are simultaneously
mounted and machined in the chucks parallely
at all stations each one having same set of
axially and / or radially moving cutting tools.

108. Basic configuration of multispindle automatic vertical lathe

109. 2.Progressively processing type :
• The spindle carrier with the blanks fitted in the chucks
on the rotating spindle is indexed at regular interval by
a mechanism.
• At each station the job undergoes a few preset
machining work by the axially and / or radially fed
cutting tools.
• The blank getting all the different machining
operations progressively at the different work stations
is unloaded at a particular station where the finished
job is replaced by another fresh blank.
• This type of lathes are suitable for jobs requiring large
number of operations.

110. 3.Continuously working type
• Like in parallel processing type, here also each job is
finished in the respective station where it was loaded.
• The set of cutting tools, mostly fed only axially along a
face of the ram continuously work on the same blank
throughout its one cycle of rotation along with the
spindle carrier.
• The tool ram having same tool sets on its faces also
rotate simultaneously along with the spindle carrier
• which after each rotation halts for a while for
unloading the finished job and loading a fresh blank at
a particular location.
• Such system is also suitable for jobs requiring very few
and simple machining operations.

111. Single spindle automatic lathe

112. • The general purpose single spindle automatic
lathes are widely used for quantity or mass
production (by machining) of high quality
fasteners
• Like bolts, screws, studs etc., bushings, pins,
shafts, rollers, handles and similar small
metallic parts from long bars or tubes of
regular section and also often from separate
small blanks.

113. • single spindle automats are :
• Preferably and essentially used for larger volume
of production i.e., large lot production and mass
production
• Used always for producing jobs of rod, tubular or
ring type and of relatively smaller size.
• Run fully automatically, including bar feeding and
tool indexing, and continuously over a long
duration repeating the same machining cycle for
each product
• Provided with upto five radial tool slides which
are moved by cams mounted on a cam shaft of
relatively smaller size and power but have higher
spindle speeds

114. Hydraulic copying (tracer controlled)
lathes
• The machine employs a dust proof electrical
system.
• The hopper feeder is hydraulic operated, while
the tailstock center is hydraulically operated to
clamp the workpiece.
• Hydraulic copying attachment were widely used
until the 1970’s as a cheap and efficient way of
mass producing.
• This is for used in different printing and textile
industries

115. • Jobs having steps, tapers and / or curved
profiles, as typically shown in Fig. are
conveniently and economically produced in
batch or lot in semiautomatically operated
tracer controlled hydraulic copying lathe.
• The movement of the stylus along the
template provided with the same desired job-
profile) is hydraulically transmitted to the
cutting tool tip which replicates the template
profile.

116. • FIG: A typical job suitable for copy turning

117. Turning attachment for lathe

118. • Machine tools in which components are machined
automatically.
• The working cycle is fully automatic that is repeated to
produce duplicate parts with out participation of operator
• All movements of cutting tools, their sequence of
operation applications, feeding of raw material, parting
off, unloading of finished parts all are done on machine.
• All working & idle operations are performed in definite
sequence by control system adopted in automatic which is
set up to suit a given work.
• Only operation required to be performed manually is
loading of bar stock/ individual casting/forged blanks
• These machines are used when production requirements
are too high for turret lathes to produce economically
AUTOMATIC LATHES

119. General Purpose Automatic lathes
• Automatic lathes are essentially used for large lot
or mass production of small rod type of jobs.
• Automatic lathes are also classified into some
distinguished categories based on constructional
features, operational characteristics, number of
spindles and applications as follows
• • Single spindle
– Δ Automatic cutting off lathes
– Δ Automatic (screw cutting) lathe
– Δ Swiss type automatic lathe
• • Multispindle automatic lathe

120. • Automatic cutting off lathe
• These simple but automatic lathes are used
for producing short work pieces of simple
form by using few cross feeding tools.
• In addition to parting some simple operations
like short turning, facing, chamfering etc. are
also done.

121. Single spindle automatic lathe
• The general purpose single spindle automatic
lathes are widely used for quantity or mass
production (by machining) of high quality
fasteners; bolts, screws, studs etc., bushings,
pins, shafts, rollers, handles and similar small
metallic parts from long bars or tubes of
regular section and also often from separate
small blanks

122. • Unlike the semiautomatic lathes, single spindle
automats are :
• Preferably and essentially used for larger volume of
production i.e., large lot production and mass
production
• Used always for producing jobs of rod, tubular or ring
type and of relatively smaller size.
• Run fully automatically, including bar feeding and tool
indexing, and continuously over a long duration
repeating the same machining cycle for each product
• Provided with upto five radial tool slides which are
moved by cams mounted on a cam shaft of relatively
smaller size and power but have higher spindle
speeds

123. Swiss type automatic lathe
• The characteristics and applications of these
single spindle automatic lathes are :
• • In respect of application :
• Used for lot or mass production of thin slender
rod or tubular jobs, like components of small
clocks and wrist watches, by precision machining;
• o Job size (approximately)
– ⎯ Diameter range – 2 to 12 mm
– ⎯ Length range – 3 to 30 mm

124. • Dimensional accuracy and surface finish – almost
as good as provided by grinding
• • In respect of configuration and operation
– The headstock travels enabling axial feed of the bar
stock against the cutting
– There is no tailstock or turret
– High spindle speed (2000 – 10,000 rpm) for small job
diameter
– The cutting tools (upto five in number including two
on the rocker arm) are fed radially
– Drilling and threading tools, if required, are moved
axially using swivelling device(s)
– The cylindrical blanks are prefinished by grinding and
are moved through a carbide guide bush as shown.

125. Multispindle automatic lathes
• Multispindle automatic lathes having four to
eight parallel spindles are preferably used. Unlike
multispindle turret lathes, multispindle automatic
lathes are;
• Horizontal (for working on long bar stocks)
• work mostly on long bar type or tubular blanks
Multiple spindle automats also may be parallel
action or progressively working type.
• Machining of the inner and outer races in mass
production of ball bearings are, for instance,
machined in multispindle automatic lathes.